Hydraulic apparatus



March 24, 1942.

E.M.PFAUSER 'HYDRAULIC APPARATUS 2 Sheets-Sheet 1 Original Filed April 4, 1956 4iii- Vv Y A iam-nii@ March 24, 1942. E; M PFAUSER 2,277,256

HYDRAULIC APPARATUS Original Filed April 4, 19364 2 Sheets-Sheet 2 N @www t l s/ Ng? g1 i t. l k v Jnverzor.- wafd/ Wijfawgen Patented Mar. 24, 1942 2,277,256 HYDRAULICv APPARATUS Edward M. Pfauser, Elm Grove, Wis.` assignor to Blackhawk Mfg. Co., Milwaukee, Wis., a corporation of Wisconsin Original application April 4, 1936, Serial No.

72,750. lDivided and this application December 20, 1937, Serial No. 180,757

(Cl. 10S-218) 2 Claims.

My invention relates, generally, to hydraulic apparatus, and it; has particular relation to high Other objects of my invention will, in part, be

obvious, and, in part, appear hereinafter.

pressure, light Weight pumps for use with metal K bending and straightening apparatus.

This application is a divisional application f my copending application, Serial No. 72,750, led April 4, 1936, now Patent No. 2,165,504, issued July 1l, 1939, which is a continuation in part of my copending application, Serial No. 4,728, led February 4, 1935, now Patent No. 2,165,503, issued July 11, 1939, both of which are assigned to the assignee of this application.

As is more completely disclosed in my copending application, Serial No. 72,750, I have provided a light weight, portable metal straightening and bending machine that is capable of developing pressures of several tons. This apparatus finds particular application in the automobile industry in which one of its chief uses is the straightening and bending of steel automobile bodies that have been deformed as a result of a collision or otherwise. In general, the apparatus comprises a ram that may be readily handled by one hand of the operator and placed in any desired operative position. Various attachments may be made to the ram plunger and cylinder to adapt it for different types of work. A high pressure iiexible hose interconnects the ram with a pump that is readily workable in the hands of an operator and which ls readily capable of developing the necessary hydraulic pressure for operating the ram. This application is particularly directed to the constructional details of the pump and the manner and means of mounting it on a portable stand.

The object of my invention, generally stated, is to provide an improved high pressure, light weight pump for use in metal bending and straigtening apparatus that shall be simple and efficient in operation and which may be readily and economically manufactured and installed.

An object of my invention is to provide a pump that is capable of developing pressures of the order of several thousands of pounds and which is readily portable.

Another object of my invention is to provide for operating a pump in the manner in which a pair of tong handles is operated and which is capable of creating relatively high pressures.

A further object of my invention is to provide for mounting a pump of this character on a portable stand in such manner that itmay be readily used by an operator without tipping over vthe stand.

My invention, accordingly, is disclosed in the embodiment hereof shown in the accompanying drawings, and it comprises the features of construction, combination of elements and arrangement of parts which will be exempliiied in the construction hereinafter set forth, and the scope of the application of which will beindicated inthe appended claims.

For a more complete understanding of the nature and scope of my invention, reference may be had to the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a perspective view of my invention with the ram mounted on a portable stand in such manner as to form a hydraulic press;

Figure 2 is a top plan view, on approximately three-quarter scale of actual size of the pump unit shown in Figure 1;

Figure 3 is a vertical sectional view on a scale similar to Figure 2, of the pump unit there shown;

Figure 4 is an elevational view, partly in section, of the pump unit shown in Figure 2; and

' Figure 5 is a sectional view taken substantially on line 5-5 of Figure 4.

As shown in Figure 1 of the drawings, a pressed metal stand 5 is provided having a series of anged trays or shelves 6, in this case three, pressed from heavy sheet stock and mounted on legs 3 which are'formed of angle iron stock, or pressed into angle iron form out of sheet stock. The corners of the trays 6 are preferably welded to the legs 3 to secure the parts rigidly and permanently together. The legs 3 are provided with caster wheels 'l so that the stand and supported parts may be conveniently rolled to any desired place on the iioor of the shop or garage. There is a peculiar utility in the stand in that it is not only a suitable support for the pump and the ram and press or either of them but also it is a convenient support for work engaging appliances. Since these appliances may be carried in the trays 6, they are not only always conveniently at hand but also they add Weight and stability to the stand so that the reacion of the pump or the added weight of a piece of Work in the press do not unbalance the stand. Since these various parts and work engaging appliances are illustrated and described in detail in my copending application of which this application is a division, they have not been shown 1n Figure 1 nor will they be described herein.

A single acting pump unit I1 is clamped to the vertically extending defining edge I8 of the top shelf i by means of fixed angle brackets I9 which are secured upon opposite sides of one of the vertical edges of the Vtop tray 6, as illustrated. These brackets I9 are adapted to support headed pins or studs which nt into slots 50 on the seat 49, Figure 2, carried by the pump unit I1. The pump unit I1 is also provided with a removable rod-like operating handle 22, which may be swung up and down to operate the pump plunger 51, Figure 3.

There is a peculiar 'advantage in the singleacting pump unit I1 disposed as shown on the stand 5 and supported waist high, in that a workman or operator can readily, by straightenlng out his arm, put substantially his entire weight upon the handle 22, thereby exerting maximum force.

One end of the stand 5 is provided with a pair of bracket members 23, only one of which is shown, suitably secured in fixed position with respect thereto, and which have laterally projecting shoulder portions 24 upon which is mounted the bottom pressure plate of a press unit indicated generally at 25.

The press unit 25 comprises a pair of yoke members or press rods 26, which, at their lower ends, pass through the base plate member 21 and are secured by suitable nuts 28 to the shoulder portions 24 of the bracket members 23. The base member 21 is of relatively solid and heavy construction, and preferably has a flat surface 29 extending between the yoke rods 26. At their upper end the yoke rods are provided with a second connecting member 30, secured thereto by means of nuts 32, the. member 30 corresponding to the member 21. The length of the yoke is thereby adjustable. Also, by removing the lower nuts 28 the yoke may be removed from the stand. The press plates 21 and 30 are provided with iiat spots so that the press may be laid in stable position on a flat support, such as a floor or bench. Extending centrally through the member 30 is an opening, corresponding to the opening 33 in the member 21, and the base of the ram unit I3 is adapted to be locked in position with respect thereto by means of the bolt 35 having an extending stud projecting through this opening.

The ram unit I3 is connected to the pump unit I1 by means of the ilexible connecting hose I6, so that the liquid discharged by the pump I1 may be transmitted to the ram unit I3, and when the relief valve 93 is opened it may be returned to the reservoir. This hose is made expressly for high pressure work and comprises a synthetic rubber inner tube about 1A" internal diameter with alternate layers of high tensile wire braid or Wrapping and layers of the rubber composition. A nal exterior coating of synthetic rubber is then applied, with the layers and coatings all being then vulcanized together.

The head end of the cylinder of the ram I3 is disposed in depending position Within the press rods 26, and serves to guide the ram plunger for movement outwardly of the ram cylinder. The threaded end of the plunger is thus moved downwardly under hydraulic pressure toward the opening 33. The outer end of the ram plunger is providedl with a threaded head, so that a suitable contacting appliance may be tted thereupon to engage the work which it is desired to operate upon. The supporting stand constitutes a frame for the pump and press. and,

as indicated, also forms a convenient receptacle and support for the various appliances which may be used in the various operations to which the machine is applied.

Referring now in detail to the construction of the pump unit I1, which is shown in Figures 2 to 5, inclusive, the unit comprises a reservoir cylinder, indicated at 45, which is threaded at its opposite ends, the outer end of the reservoir tube or cylinder receiving the reservoir cap member 46, which is provided with a suitable opening through which oil or other liquid may be admitted to the interior of ,the reservoir to charge the same. In practice I nd that light mineral oil, such as S. A. E. #10W may be employed, the capacity of the pump with the hose and ram being about one quart. This opening is preferably closed by the filler plug 41, suitable gasket means being provided for preventing leakage.

A foot rest and clamp member, indicated generally at 48, is clamped about the outer end of the reservoir adjacent the cap 46. It preferably has its upper surface serrated in order to provide for rm gripping thereof by the foot of the operator when the pump unit is disposed for operation upon the oor. The clamp 48 is provided with oppositely extending lugs or feet 49 at the lower portion thereof, which feet portions are provided with slots 50 extending lengthwise from one end thereof, the slots 58 receiving securing means, such as the headed pins 20, for holding the feet of the pump I1 to the brackets I9 of Figure l. Suitable clamp means, such as the hand wheel 52 and threaded stem shown in Figure 1, may be provided for engagement with the filler cap 41 for thrusting and holding the pump unit in position by causing the slots 50 at each end of the pump to pass under and be held by the headed pins or rivets 20. The pump reservoir is made of considerable length for a number of reasons. Its length renders it suitable for manual operation in the manner of the handles of a pair of tongs, while the extended base allows maximum seating efliciency on the stand. Also, by reason of its length, the operators feet can be disposed in a more balanced position when it is placed on the floor for operation.

At its opposite end the reservoir tube 45 is threaded into a socket in the pump frame1 indicated generally at 55, which frame comprises a pump cylinder 56. The pump plunger 51, which is in the form of a cylindrical member approximately V2" in diameter, is adapted to have reciprocatory movement in the pump cylinder 56. 'I'he upper end of the pump plunger 51 has a head which is slotted transversely, as shown at 58, to receive a cross pin member 59. The member 59 is preferably locked in position by means of cotter pins 60. The cross pin 59 is slabbed off or flattened on its bottom side and the ends are carried by extending web portions 62 of a rocker beam 63, which beam is pivoted at 64 about an upwardly extending bracket portion 65 of the base 55. The centers of pins 59 and 64 are laterally spaced approximately 1*/8 inches. Upon rocking movement of the beam 53 by means of the handle 22, the pin 59 engaged in the slotted end 58 of the plunger 51 provides for reciprocatory movement of the plunger within the cylinder 56. The pin 59. cannot turn in the slot. It has a small sliding movement in the slot, due to its arcuate travel. Projecting ends 66 of the beam 63 serve as stop means for limiting the upward movement of the plunger 51, so that it will not be accidentally withdrawn too far or disengaged from the pin 59. The handle 22 may be of any desired length, but I nd that a length of about 26 inches is preferable both for convenience in operation and for application of pressure. Thus with the handle length of twenty-six inches working on a half inch diameter plunger at a lever arm of one and one-eighth inches the unit pressure upon the liquid in the pump cylinder will be of the order of two hundred times the numerical value of the pressure put upon the end of lever 26.

The beam 63 is provided with a horizontally extending socket the bottom of which is threaded. This socket is engaged by the handle 22 for rocking the beam about the pivot 64. lengths of handle are provided. However, when the pump unit I1 is disposed upon theoor, it may be desirable to provide for vertical disposition of the handle 22, in which case the handle is inserted into the opening 61 formed in the beam 53, and suitably engaged within the threaded portion 68 thereof. In thatposition preferablya greater length of handle is used. The lower end of the vertical socket of the beam 63 is adapted to have abutting engagement with a portion of the base 55 indicated at 69, for the purpose of limiting downward movement of the plunger 51, v

A packing spreader is indicated at 10, and chevron packing is disposed between the same and the gland nut indicated at 12, which is adapted to be disposed within a counterbored portion of the pump cylinder 56, to provide a suitable packing gland for preventing escape of liquid along the` surface of the plunger 51. Suitable resilient rings of packing 1I and 13, such as oil proof rubber, cork or the like, are disposed above the gland follower` 12. Above the packing 13 is threaded the retaining nut indicated at 14, which holds the packing in compression between the gland follower 12 and the retaining nut 14.

In the operation of the pump shown in Figures l to 5, as the pump plunger 51 is moved upwardly, suction is created in the cylinder 56, which results in drawing of fluid from the reservoir 45 through the filter or screen 15 and the inlet opening 16 formed in the base 55, through the passageway 11 shown in Figure 5 to the angularly extending passageway 18 shown in Figure 4. A suitable ball inlet check valve 19 is provided adjacent tlie upper end of the passageway 18, and is raised by the suction in the pump cylinder 56, providing for flow of fluid from the passageway 18 to the horizontally extending passageway 88 which leads into the lower end of the pump cylinder 56. The passageway 80 is suitablyclosed at its outer end by means of the threaded plug 82.

'I'his serves. to ll the pump cylinder beneath the plunger with liquid to be discharged. Upon downward movement of the handle 22, the pump plunger 51 displaces the liquid from cylinder 56 under pressure, and this pressure serves to close the ball check valve 19. The liquid is forced out through the passageway 88, and opens the ball check valve 83, which normally -is closed by the compression spring 84 disposed between the check valve and the valve plug 85, and the liquid ows into the enlarged bore 86 of the discharge passageway.

From adjacent the upper end of the bore 86, the liquid flows through the passageway 81 to a transversely extending passageway 88 drilled through the base 55, the passageway 81 being closed at its outer end by the plug 89. From the passageway 88 the liquid ows outwardly Several through the outlet opening 90, and into the iin-xible hose I6, the coupling of which is threaded into the recess 92.

To relieve the pressure upon the ram unit the release valve 93, which has a needle valve face 94 at its inner end, is threaded outwardly with respect to the packing nut 95, which closes the bore through which the spindle extends. The nut 95 is adapted to compress the packing 96 to prevent leakage of oil therepast. Backing off of the spindle 93 and valve 94 allows the oil from the chamber and the passageway 8B to pass through the passageway 91 into the reservoir 45.

It is thus apparent that upon reciprocation of the plunger 51, liquid is drawn from the ieservoir and forced into the ilexible hose I6. When the ram has performed the desired work the valve 94 is opened and the pressure is released,

the liquid being returned to the reservoir 45.

The pump unit I1 shown in Figures 1 to 5 is adapted for operation when h-eld in the hands. This is advantageous where no suitable support for `the pump can be provided, due, for example, to the position occupied by the operator, or due to the length of the hose being insuicient tol permit the pump to be carried to a suitable support. The-handle 22 employed'in that case is of just about the same length as the barrel of the reservoir which forms a hand hold. The operator grasps the handle 22 in one hand and the barrel 45 in the other and works the pump like the handles of a pair of tongs, or the handles of a pair of hedge shears. Or the operator may place the barrel 45 against his body and pull on the handle 22. 'I'he stop 68--69 prevents pinching of his fingers between the handle 22 and barrel 45 or plate 48. The stroke may be made anywhere between stops 66 and 68. Since the total weight of the pump unit and handle is less than 14 pounds, it is obvious that it can be readily manipulated in the hands.

The pump and reservoir unit may be considered as consisting of two handle members hinged together and each supporting one of the cooperating parts of the hydraulic pump. The handle member which contains the cylinder is hollow to provide a reservoir for the hydraulic medium. It also contains the various passageways and valves and supports the connection for the exible hose. The capacity of the reservoir is such as to provide adequate liquid within the capacity of the ram unit to receive the same. When the pump and reservoir unit is supported in the hands of the operator the natural tendency is to allow the two handle members to be inclined downwardly assuring that the entire contents of the reservoir are available to the pump.

Since certain changes may be made in the above construction and diierent embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a device of the class described, a portable hydraulic pump comprising a frame member having a cylinder, check valve for said cylinder, a piston for the cylinder,- a hose coupling socket connected through the discharge check valve to said cylinder, a tubular reservoir member communicating through the inlet check valve with said cylinder and extending substantially at right angles thereto, a manually controlled by-pass valve from said socket to said reservoir member, said reservoir member comprising a. relatively long tubular casing rigid with the frame and suitable to serve as a handle member, a beam pivoted on said frame member for operatingthe pump plunger, a handle member coupled to the beam and disposed to swing in substantially the same plane as the reservoir casing whereby the pump is capable of being operated by relative movement of said handle members toward and away from each other, and supporting means for the frame member and the reservoir member respectively, means carried by the outer end of the reservoir member for holding said reservoir member on the floor, said beam having a horizontal handle receiving socket and a vertical handle receiving socket for optional attachment of the handle in one position or the other.

2. In a device of the class described, the combination of a pump and reservoir unit comprising a pump frame with a rigid hollow extension forming a reservoir, said frame having a pump cylinder with a relatively small bore and a pump plunger working in said bore, said pump frame having a hose tting comprising a discharge outlet for the pump, there being a passageway containing a discharge check valve between the cylinder and the said outlet, and an inlet passageway between the bottom of the reservoir and the cylinder, the reservoir having its longitudinal axis extending laterally vfrom the pump frame and in a direction transverse to the bore of the cylinder and serving as a. rigid leverage extension of the pump frame, an operating beam connected to the piston and pivoted to the pump frame to swing in the plane of longitudinal axis of the reservoir, a handle forming a rigid leverage extension of the beam, said piston being single acting and making its discharge stroke when the handle and reservoir are moved toward each other, whereby the reservoir may be grasped in one hand of the operator and the handle in the other hand of the operator to actuate the unit while the same is supported solely by the hands of the operator, a high pressure ilexible hose having a coupling connected to said hose tting, and foot members for said pump and reservoir unit for supporting the unit upon a horizontal support on the ground, said meam having a vertical socket for receiving the handle to permit the operator to stand up to operate the pump when the unit is mounted on the ground.

EDWARD M. PFAUSER. 

